Robert Bowers, the suspect in Saturday’s deadly shooting spree in Pittsburgh, appears to have hated Jews for a variety of reasons, but one anti-Semitic trope in particular seems to have motivated him in the days prior to the shooting, and may have even played a role in his decision to unleash his hateful attack: the common white supremacist conspiracy theory that Jews are behind efforts to impose mass immigration on the United States, with the goal of harming or destroying the white race.

The last post made to the social networking account believed to belong to Robert Bowers, the suspect in Saturday’s deadly shooting spree at the Tree of Life synagogue in Pittsburgh, claimed that “HIAS [Hebrew Immigrant Aid Society] likes to bring invaders in that kill our people. I can’t sit by and watch my people get slaughtered. Screw your optics, I’m going in.” The post, made just a short time before the attack on the synagogue began, seemed to be an explanation or rationale for the attack.

An examination of what is believed to be Bowers’ account on Gab, a social networking site favored by white supremacists, reveals a deep-seated hatred of Jews. A month ago, the account referred to Jews as “all the vile degenerate oven dodgers,” saying it was time for them to “convert your stuff to shekels and flee. Time is critical.”

The account’s owner appears to have hated Jews for a variety of reasons, but one anti-Semitic trope in particular seems to have motivated him in the days prior to the shooting, and may have even played a role in his decision to unleash his hateful attack: the common white supremacist conspiracy theory that Jews are behind efforts to impose mass immigration on the United States, with the goal of harming or destroying the white race.

The account repeatedly shared others’ Gab posts and images amplifying the anti-Semitic theme of Jews driving immigration. One representative share was a post by user “Black Pilled” intimating that Jews are behind the controversial caravan of asylum seekers making its way from Central America to the United States. The post asks, “Why are Jewish groups using their trucks to transport invaders to our border?” Another comment, originally posted by Johnny Benitez, suggested the same thing and declared, “We are being destroyed, not by a superior army or an act of God, but by our fear of being called anti-[S]emites.”